>it's utterly vital for Israeli survival to have the threat of American nuclear reprisal at their beck and call
(1) Why exactly do you think Israel has US support at their beck and call? I can tell you Israelis definitely don't think so. (2) Why does Israel need it, when - following the collapse of the USSR which was the main lifeline of other Mideast forces - it now has the most powerful military in the region? and (3) Israel has its own nukes since the '60s.
American support for Israel started only in the early '70s, after Israel proved itself a useful asset by winning the Six Day War, without any US support and as counterbalance for the USSR support of Arab nations. Israel is one of very few nations in the world (certainly the western world) which the US didn't have to send its military to protect at some point.